Switch structure and combination thereof with overload relay and push button



1967 J. J. GRIBBLE ETAL 3,304,522

SWITCH STRUCTURE AND COMBINATION THEREOF WITH OVERLOAD RELAY AND PUSH BUTTON Original Filed June 29. 1961 5 Sheets-Sheet 1 a g f rgvgwzog- &01 TTORNEY.

Feb. 14, 1967 J. J, GRIBBLE ETAL 3,304,522

SWITCH STRUCTURE AND COMBINATION THEREOF WITH OVERLOAD RELAY AND PUSH BUTTON Original Filed June 29, 1961 5 Sheets-Sheet 42 a; E 62 42 Y Ill! Feb. 14, 1967 J. J. GRIBBLE ETAL 3,304,522

SWITCH STRUCTURE AND COMBINATION THEREOF WITH OVERLOAD RELAY AND PUSH BUTTON Original Filed June 29. 1961 Sheets-Sheet 4 J .ml. .11. ULJ

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Feb. 14, 1967 J. J. GRIBBLE ETAL 3,304,522

SWITCH STRUCTURE AND COMBINATION THEREOF WITH OVERLOAD RELAY AND PUSH BUTTON Original Filed June 29. 1961 5 Sheets-Sheet 5 INVENDTORZ Q ATTORNEY.

United States Patent ()fifice 3,304,522 Patented Feb. 14, 1967 3,364,522 SWITCH STRUCTURE AND COMBINATION THEREOF WITH OVERLQAD RELAY AND PUSH BUTTON Joseph J. Gribble and Kenneth ll. Marien, Milwaukee, Wis., assignors to Square 1) Company, Park Ridge, 111., a corporation of Michigan Original application June 29, 1961, Ser. No. 12tl,72:5, now Patent No. 3,235,686. Divided and this application July 16, 1965, Ser. No. 472,59

7 Claims. (Cl. 3352tl2) This application is a division of our copending application No. 120,725, filed June 29, 1961, now US. Patent 3,235,686.

This invention relates to an electromagnetically operated switch, and more particularly to the combination thereof with an overload relay or a push button switch or both.

Electromagnetic switches, as well known in the art, generally include a plurality of stationary contacts and a plurality of cooperating electromagnetically operated'movable contacts. Various line and load terminals are provided for connecting the switch to power and control circuits. One of the disadvantages of prior electromagnetic switches of this general character is the difilculty of servicing them. In general, the prior switches are so arranged that a large number of wires must be disconnected and reconnected in order to install the switches, to remove the switches from their installed positions, or to remove and replace other switches or relays operatively associated therewith.

The magnetic switch disclosed herein comprises essentially a base having a cavity therein, which is open at the top of the base, a magnet, movable contact assembly, and a cover. All of the stationary contacts are mounted in the base so as to be readily accessible for servicing merely by removing the cover and the magnet and movable contact assembly. The terminals for the stationary contacts also are mounted in the base and are accessiblefor making connections thereto while the remainder of the switch is undisturbed, even the cover remaining in lace. p Furthermore, the magnet and movable contact assembly is one which can be readily removed as a unit simply by removing the cover to expose the assembly and then lifting the assembly as a unit from the base. The connections of the operating coil are made simply by restoring the assembly to its position on the base. The assembly can be installed readily merely by placing'it in the base with certain of its portions in engagement with suitable guideways formed in the base, placing the cover thereover, and then pressing the cover to closing position and securing it in position by a pair of screws which hold the cover in place and thereby also hold the assembly in place.

A carrier for the movable contacts can be easily detached from the assembly and the movable contacts can be removed from the carrier either while it is connected to, or disconnected from, the assembly. Further, the assembly is so arranged that an armature may be removed from the remainder of the assembly very readily, and the movable contact carrier and its supporting and operating parts can be detached from each other and removed for replacement or repair. A number of parts of the magnetic assembly are so held in assembled relation and supported resiliently when in operating position as to absorb shocks. Proper alignment of the magnet armature and stationary pole piece are assured.

In accordance with this invention, the switch is also arranged for detachable snap fastening engagement with an overload relay or a push button switch, or both.

The electromagnetic switch is particularly adaptable for connection with a specific type of overload relay having a plurality of external prong terminals. The switch has terminals complementary to the prongs and adapted for receiving the prong terminals, respectively and concurrently, simply by moving the overload relay relatively toward the electromagnetic switch while in proper alignment therewith. A push button switch may similarly be mounted on the electromagnetic switch.

Various other objects and advantages will become apparent from the following description wherein reference is made to the drawings, in which:

FIG. 1 is a top plan view of an electromagnetic switch embodying the principles of the present invention;

FIG. 2 is a front elevation of the switch illustrated in FIG. 3;

FIG. 3 is a right end elevation of the switch illustrated in FIGS. 1 and 2;

FIG. 4 is a bottom plan view of the switch illustrated in FIGS. 1 through 3;

FIG. 5 is a front elevation of the switch illustrated in FIG. 1, but with the cover, the baseplate, and the electromagnetic assembly removed;

FIG. 6 is a vertical cross sectional view taken on the line 66 in FIG. 5; 7

FIG. 7 is a longitudinal horizontal sectional view taken on the line 77 in FIG. 5;

FIG. 8 is a view similar to FIG. 5 but with only the electromagnetic assembly of the switch in place;

FIG. 9 is a plan view, partly in section, of the bottom of the structure illustrated in FIG. 7, but with the structure turned so that the base is disposed horizontally for convenience in projection between FIGS. 9 and 10;

FIG. 10 is a left end view, partly in section, of the structure as positioned in FIG. 9, part of the cover and easing being shown in section for clearness in illustration;

FIG. 11 is a fragmentary rear elevation of the supporting means of the movable contact carrier, the carrier being omitted for clearness in illustration;

FIG. 11A is a fragmentary front elevation of the supporting means shown in FIG. 11, with the carrier connected thereto;

FIG. 12 is a right end elevational of the structure illustrated in FIG. 11;

FIGS. 13, 14 and 15 are a top plan view, side elevation and rear elevation, respectively, of an overload relay structure combined with the present electromagnetic switch;

FIGS. 16, 17 and 18 are a top plan view, right end elevation, and rear elevation, respectively, of a push button assembly arranged to be combined with the electromagnetic switch of the present invention;

FIG. 19 is a perspective view of the combined switch and relay viewed generally from the front; and

FIG. 20 is a side elevation of the electromagnetic switch, relay, and push button assembly connected in operating position with respect to each other.

Referring first to FIGS. 1 through 4, the electromagnetic switch, indicated generally at 1, comprises an insulating, molded, box-like base 2 mounted on a metal base plate 3 which has an aperture 4 for receiving a suitable screw or bolt for securing the switch in a suitable enclosure or on an open flat panel.

The base 2 is provided with stationary contacts and terminals therefor, later to be described. A magnet and movable contact assembly are carried by the base and enclosed by a suitable cover 5 of insulating material secured in place on the base by two bolts 6 which engage suitable threaded fittings 7, see FIG. 10 embedded in the base 2. The cover 5 is provided with a window 8 through which a portion of the coil and the armature of the electromagnetic assembly and its supporting parts are observable for determining indicia on the coil and whether or not the armature is in proper operative posi tion.

As best shown in FIGS. 5, 6, and 7, a plurality of stationary contacts 10 are provided in the base 2 and are arranged in two parallel rows. Each contact 10 is screw fitted into a conventional metal threaded insert 11 embedded in the base 2, and each is connected to a terminal member 12 which has a horizontal portion 13 and a vertically extending portion 14 tapped to reccive screws 15 and 16, res ectively, for clamping the end portions of respective wires, not shown. to the associated one of the portions 13 and 14.

The horizontal portions 13 are exposed exteriorly of the base 2 both at the bottom and at the top, facing downwardly and upwardly, respectively, so that wires can be connected thereto readily from the exterior of the base by the screws 16 while the cover is in place. The vertical portions 14 are exposed exteriorly of the base 2 both at the upper and lower margins of the base so that the wires can be connected thereto readily by the screws 16 when the cover 5 is in place. With this arrangement, connections can be made to the stationary contacts with-out removing the cover 5 and without disturbing any of the other parts of the switch. Suitable vertical channels 19, best shown in FIGS. 1 and 2, are provided in the rear face of .the base 2 so that the wires can be disposed between the rear face and the base plate 3.

In order to receive and support the magnet and movable contact assembly, the side walls of the base are provided with respective suitable integral guideways 20, as shown in FIGS. 5 and 6, which extend from the open front of the base rearwardly and which are formed by the associated side wall of the base and adjacent faces of integral guide bars 21 on the associated side wall. The bars 21 stop part way inwardly from the open front and the forward ends provide forwardly facing stop shoulders 22. Between its sides the base 2 has intermediate walls 23 which are in parallel spaced face-to-face relation from the side walls and from each other and terminate a distance inwardly from the open front. Except for the intermediate wall 23, the walls 23 have forwardly open guideways 24 therein. The intermediate one of the walls 23 has a forwardly open .guideway 26 vwhich is wider than the guideways 24. The guideways 24 and 26 terminate short of the back wall of the base 2 so that the rearward portions of the walls 23 shield the contacts in each row from each other.

The magnet and movable contact assembly, shown best in FIGS. 9 and 10, can be installed and removed from the base 2 as a unit. It comprises generally a pole piece 39 which, in horizontal projection, is of 'E-shaped configuration, having outer legs 31 and an intermediate leg 32. The central leg 32 is accommodated within the axial passage of a coil 33. An armature 34 is arranged to cooperate with the core 30 and is provided with outer legs 35 and a central leg 36 complementary to and aligned endwise of the coil 33 with the legs 31 and 32, respectively, the leg 36 also being accommodated within the coil. The legs 31 are shaded with suitable shading coils 37.

The aramature 34 is connected to a movable contact carrier 40 so as to move the carrier 40 forwardly and rearwardly upon like movement of the armature 34.

For assembling both the armature 34 and the carrier 40 with the coil 33 and guiding them during operation, suitable guide means 41 are provided. The guide means 41 comprise a pair of parallel arms 42 which extend through the axial passage of the coil and fit therein with sufiicient clearance so that both the armature and the movable carrier 40 are constrained thereby to move in proper relation with each other and alignment with the coil 33 and stationary pole piece 30.

As mentioned, both the armature 34 and the movable contact carrier are readily removable from the magnet and movable contact assembly. Therefore, the arms 42 are provided with forward end portions 43 which are spaced apart less than the thickness of the armature 34, and receive the armature therebetween upon springing them slightly apart by pressing the armature edgewise therebetween. The arms then grip the armature 34 under resilient clamping pressure. The forward end portions 43 have suitable apertures 44 and the armature 3 had a passage 45 at its midportion. The apertures 44 and passage 45 are aligned with each other when the armature 34 is in proper position. A suitable pin 46 extends through the aligned apertures 44 and passage 45 for securing the armature rockably on the forward ends of the arms 42. The pin 46 has a head 47 at one end, a tapered cam surface 48 at the other end, and an annular groove 49' adjacent the cam and arranged that when the head 47 is seated against the outer face of one arm portion 42 the groove 49 is disposed outwardly just beyond the out-er face of the other arm 42. A U- shaped snap fastening spring 50 is carried on the armature 34 with its legs arranged so as to be spread by the cam surface 48 and to snap into a seated position in the groove 49 for retaining the pin 46 in place. In order that the spring 50 be retained in position and not lost while the parts are disassembled, a suitable holder 52 is secured to one face of the armature and includes two wall portions 53 juxtaposed against and secured to the armature 34 and an intermediate wall portion 54 spaced outwardly beyond the outer face of the arm 42 at the adjacent side of the armature 34. Passages 59a are provided at the ends of the wall portion 54 so that both legs of the spring 50 can be passed therebetween and overlie the arm portion. One end of the spring 50 is received in a suitable notch 58 in a lug 59 at one end of the holder 52 so as to prevent accidental displacement of the spring 50.

The arms 42 are preferably a portion of a yoke having a base portion 64), FIGS. 11 and 12. In order to support the carrier 40 on the arms 42, a suitable fitting is mounted on the arms 42 for sliding therealong. In the form illustrated, the fitting comprises two side members 61 adapted to engage the outer face of the arms 42, respectively, an intermediate bridge portion 62, and snap fastening end portions 63 joining the members 61. Each end portion 63 has an outer marginal portion in the form of a pair of rearwardly extending tongues 64. Due to the shape and resilience of the material, the tongues 6 of the one member 61 may be pressed toward those of the other and, when released, restore themselves to their normal spaced position. Each of the arms has at its upper end snap fastening shoulders 66 and 67 for a snap fastening engagement with the movable contact carrier 40.

The movable contact carrier 40 has, at its midportion a rearwardly open channel portion 70, FIG. 11A, the margins of which, at the open side of the channel portion, are provided with shoulders 71 and 72 which are arranged to be placed in snap fastening engagement with shoulders 66 and 67, respectively. Due to resiliency of the tongues 64, the carrier 46 can be installed in place by merely snapping the tongues 64 into position between the sides of the channel so that the shoulders 66 and 67 engage the shoulders 71 and 72, respectively. The slide members 61 have forwardly extending marginal flanges 73 which engage the upper and lower wall surfaces of the carrier 46 adjacent the ends of the channel 70 and prevent displacement of the carrier 40 endwise of the channel 76.

As shown in FIGS. 9 and 10, the carrier 40 ha a number of depending integral frames 75 in each of which is a movable contact member 76. Each contact member 76 rests against the inner face of the outer wall member of its frame 75 and is held thereagainst by a follower 77 which is pressed theretoward by a suitable spring 78.

As mentioned, the end walls of the base 2 are provided with guideways 20 and 21 and the outer intermediate walls 23 are provided with guideways 24. These receive the carrier 40, engaging its upper and lower faces and guiding the carrier along a proper path to dispose its movable contact members in proper position so that the movable contacts are in proper contacting relation with the stationary contacts in the base. Further guiding of the carrier 40 is provided by the guideway 26 which engages the side members 61 of the fitting.

A pair of coil springs 81 are received at one end in recesses 81 in the base 2 and are received at the other end on bosses 82 on the rear face of the carrier 40, and yieldably urge the carrier 41) to its forward or contact open position.

The guides 20 in the base are provided for guiding the pole piece 30 into place. For this purpose, the pole piece 30 has opposite end portions 84, as illustrated in FIG. 9, which slidably fit in the respective guides 26 with operating clearance so that the pole piece can move forwardly and rearwardly. A leaf spring 85 is mounted on the rear of the pole piece 30 and is convex forwardly. Its outer ends engage the respective shoulders 21 and thereby yieldably urge the pole piece forwardly and yieldably support it so that it can shift slightly and accommodate the faces of its poles properly to the precisely formed pole faces of the armature 34.

The coil 33 is of the type in which a winding is embedded in a molded body 35a of hard insulating material. The coil is provided with two contact tabs 86 which constitute its terminals. Mounted in the base 2 are fiat spring contacts 87 and adapted to engage the respective tabs 86 under yielding pressure so as to connect the coil to terminals 88 on the base 2 when the coil is pressed into seated position.

In order to hold the coil 33 and the pole piece 3t) in place, the molded body of the coil body 85a is provided with two integral diagonally opposite lugs 89, FIG. 8, each having guide surfaces 90 which engage respective cooperating guide surfaces 91 on a pair of lugs 92 integral with the base 2. The lugs 92 on the base support the terminals 88 which are connected to the spring contacts 87, respectively.

When the rear faces of the lugs 89 seat on the forward ends, indicated at 95 in FIG. 10, of the lugs 92 of the base, the lugs and guide surfaces 91) and 91 hold the coil body 85a in position and, at the same time, the coil body bears against the pole piece 30 and holds it in position against the resistance of the leaf spring 85.

Each of the lugs 89 is provided with an aperture 96 through which the cover screws 6 extend so that their inner ends can be placed in threaded engagement with threaded fitting '7 which are molded into the lugs 92 of the base. When the cover is drawn into place by the screws 6, it engages the forward face of the lugs 89 of the coil body 85a and forces them rearwardly against the forward ends 95 of the lugs 92 on the base so that the coil body 85a is clamped tightly to the base by the screws 6 and the cover 5. This operation also secures the pole piece 30 in position.

In accordance with this invention, means are provided to facilitate use of the switch just described at times in combination with an overload relay 111-0 illustrated in FIGS/13 through 15 and in FIGS. 19 and 20. The relay there shown is fuily set forth and described in the application of Carl A. Brandenberg, Serial No. 116,091, filed June 1961, now US. Patent No. 3,179,757, issued April 20, 1965. Insofar as concerns the present invention, the relay 100 includes a housing 101 having a base plate 102, the upper end of which can be connected to the base plate 3 of the switch, as by a pair of screws. The relay 100 is provided with a plurality of parallel rigid contact prongs or male connectors 103 which extend outwardly of the casing 101 and are positioned so that, by moving the relay into proper position for connecting it to the base plate 3 of the electromagneti switch, the prongs 103 are received in position for clamping to the terminals 12 of the electromagnetic contact or, as illustrated in FIGS. 6 and 10, by the screws 16.

Likewise, it is desirable to support a manually operable switch device, such as a push button assembly, on the switch. In such a case, a push button assembly such as illustrated in FIGS. 16 through 18 and FIGS. 19 and 20 may be provided. The push button assembly comprises a two part casing in which suitable push button switches 111 are mounted, the 'wires therefrom being lead to the switch. Suitable screws 112 are provided for holding the parts of the casing 110 together and for receiving snap fastening elements 113 on the casing 110 for fastening the casing to the switch.

For this purpose, the cover 5 of the switch is provided with sockets 114 which face forwardly and are arranged to receive suitable prongs 115 on the elements 113. Each of the elements 113 is in the form of a bracket having its prongs 115 arranged to overlie the top of a casing 110 and, at its forward end, is secured in place by the associated screw 112. Each prong 115 extends rearwardly from the casing 110. At the rear of the casing 110, each element 113 is provided with a downwardly extending portion 116 which terminates at its lower end in a horizontal arm 117. The arms 117 extend rearwardly into position to press firmly against the under face of the cover 5 of the electromagnetic switch when the prongs 115 are in the sockets 114.

Suitable reinforcing webs 118 are provided for reinforcing the elements 113. On the lower ends of the webs are abutments 119 which engage the rear face of the casing 110 so as to stabilize the assembly.

Thus, in order to mount the push button on the electromagnetic switch, all that is necessary is to align the prongs 115 with the respective sockets 114 and press the push button casing toward the switch, thus snap fastening it detachably in place. The webs 118 are provided with holes 120 through which wiring may be passed so that the elements support the wires neatly.

Having thus described our invention, we claim:

1. :In combination, a switch device including a mounting plate, an insulated base mounted on the plate, said base having a front wall, a rear wall, and lateral walls, a plurality of sets of stationary contact assemblies disposed in parallel rows on the base, each of said sets providing a pair of spaced stationary contacts having contact portions on opposite sides, respectively, of a median plane extending forwardly and rearwardly and laterally of the base, said contacts being spaced between the front and rear walls and having intermediate portions, extending from the contact portions, with terminal portions externally accessible at the front of the base clamping members carried by the external portions of the terminal portions, respectively, for clamping conductors to the terminal portions, respectively, a movable contact assembly carried by the base to be removable as a unit from the base, said movable contact assembly including a contact carrier movable linearly generally parallel to the median plane in a direction toward and away from the stationary contact assemblies between two positions, a plurality of movable contacts carried by the carrier so as to be separated from the contact portions when the carrier is in a first of the said two positions and to engage and bridge the contact portions of the pairs of stationary contacts of each set and complete an electric circuit through each set when the carrier is in a second of said two positions, and an electromagnet having a magnet coil for moving the carrier from the first to the second position upon energization of the magnet coil by a control circuit,

an overload relay device, means detachably connecting the relay device in a fixed position relative to the base,

spaced rigid male connector in fixed positions, respectively, on the overload relay device, and extending end-wise, exteriorly thereof and clamped by the clamping members in contact with the terminal portions, respectively, and said fixed positions of the male connectors and the positions of the terminal portions being such that the male connectors are alignable with, and while aligned are receivable endwise concurrently in a clamping position relative to their associated terminal portions of the switch device by bodily relative movement of the devices toward each other endwise of the male connectors.

2. The structure according to claim 1 wherein the overload relay device includes a mounting plate, an insulated housing mounted on the mounting plate of the relay device, and a detachable threaded connection is provided between the mounting plates of the devices for holding the devices in fixed position relative to each other with the male connectors and associated terminal portions in engagement.

3. The structure according to claim 1 and further including a support for the electromagnet on the base, a cover engaging portions of the electromagnet for positioning the electroma'gnet on the support, means for securing the cover in fixed position relative to the base, a manually operable switch having control circuit contacts, supporting means supporting the manually operable switch on the switch device, said supporting means including complementary interengageable snap fastening means on the supporting means and cover and at least one arm on the manually operable switch and extending therefrom and detachably engaging an exterior wall of the switch device.

4. The structure according to claim 1 and further including a mounting plate for the overload device, said plate having a margin positioned to be connecta'ble with a margin of the mounting plate of the switching device,

connecting means for immovably connecting the margins of the mounting plates together,

a housing for the overload device mounted on the plate of the overload device, and having a front wall disposed to provide access to the connecting means along an axis perpendicular to the mounting plate of the overload device, and having a rear wall,

a plurality of current responsive means in said housing of the overload device in spaced relation to each other,

said rigid male connectors being connected to the current responsive means, respectively,

wire connecting terminals on the current responsive means, respectfully, and accessible exteriorly of the housing of the overload device, each current responsive means including additional means operative in response to the current fiow between its male connector and wire connecting terminal to provide a mechanical output when said current flow exceeds a predetermined value, and

a manually operable switch carried by the housing of the overload device and having normally closed contacts in said circuit and which are actuated to move to a circuit interrupting position by the mechanical output of any one of the current responsive means.

5. The structure according to claim 4 wherein a support for the electromagnet is provided on the base of the switch device, the switch device includes a cover detachably connected to the base of the switch device and having portions engaging portions of the electromagnet for positioning the electromagnet on the support, and

supporting means for mounting the manually operated switch on the switch device, including complementary engageable snap fastening means on the supporting means and cover, and at least one arm extending from the supporting means and detachably engageable with an exterior wall of the switch device.

6. In combination, a first switch device including a casing having a base portion and a cover portion; sets of stationary contacts carried by one of said portions; sets of movable contacts carried by one of said portions and cooperable with the stationary contacts, respectively, terminals for the stationary contact on one of said portions; a second switch device connected to at least one of the terminals; and complementary interengageable snap fastening means on the devices, respectively, engageable with each other for securing the devices in fixed position relative to each other; characterized in that the snap fastening means include a passage in one of said devices, and resilient means on the other device including a tongue receivable in the passage in resilient engagement with a wall portion of the passage.

7. The structure according to claim 6 wherein the snap fastening means also includes at least one arm on one of the devices, which arm extends exteriorly therefrom and detachably engages an exterior wall of the other of the devices.

Reterences Cited by the Examiner UNITED STATES PATENTS 2,662,135 12/1953 Seaton 200-104 X 2,794,093 5/1957 Morschel 200-404 3,011,099 11/1961 Ford 200 133 3,146,325 10/ 1964 Gribble 200-487 3,179,757 4/1965 Brandenbcrg 200124 3,221,131 11/1965 Bury 200-168 3,235,686 2/1966 Gribble et a1 200-87 BERNARD A. GILHEANY, Primary Examiner.

J. BAKER, Assistant Examiner. 

1. IN COMBINATION, A SWITCH DEVICE INCLUDING A MOUNTING PLATE, AN INSULATED BASE MOUNTED ON THE PLATE, SAID BASE HAVING A FRONT WALL, A REAR WALL, AND LATERAL WALLS, A PLURALITY OF SETS OF STATIONARY CONTACT ASSEMBLIES DISPOSED IN PARALLEL ROWS ON THE BASE, EACH OF SAID SETS PROVIDING A PAIR OF SPACED STATIONARY CONTACTS HAVING CONTACT PORTIONS ON OPPOSITE SIDES, RESPECTIVELY, OF A MEDIAN PLANE EXTENDING FORWARDLY AND REARWARDLY AND LATERALLY OF THE BASE, SAID CONTACTS BEING SPACED BETWEEN THE FRONT AND REAR WALLS AND HAVING INTERMEDIATE PORTIONS, EXTENDING FROM THE CONTACT PORTIONS, WITH TERMINAL PORTIONS EXTERNALLY ACCESSIBLE AT THE FRONT OF THE BASE CLAMPING MEMBERS CARRIED BY THE EXTERNAL PORTIONS OF THE TERMINAL PORTIONS, RESPECTIVELY, FOR CLAMPING CONDUCTORS TO THE TERMINAL PORTIONS, RESPECTIVELY, A MOVABLE CONTACT ASSEMBLY CARRIED BY THE BASE TO BE REMOVABLE AS A UNIT FROM THE BASE, SAID MOVABLE CONTACT ASSEMBLY INCLUDING A CONTACT CARRIER MOVABLE LINEARLY GENERALLY PARALLEL TO THE MEDIAN PLANE IN A DIRECTION TOWARD AND AWAY FROM THE STATIONARY CONTACT ASSEMBLIES BETWEEN TWO POSITIONS, A PLURALITY OF MOVABLE CONTACTS CARRIED BY THE CARRIER SO AS TO BE SEPARATED FROM THE CONTACT PORTIONS WHEN THE CARRIER IS IN A FIRST OF THE SAID TWO POSITIONS AND TO ENGAGE AND BRIDGE THE CONTACT PORTIONS OF THE PAIRS OF STATIONARY CONTACTS OF EACH SET AND COMPLETE AN ELECTRIC CIRCUIT THROUGH EACH SET WHEN THE CARRIER IS IN A SECOND OF SAID TWO POSITIONS, AND AN ELECTROMAGNET HAVING A MAGNET COIL FOR MOVING THE CARRIER FROM THE FIRST TO THE SECOND POSITION UPON ENERGIZATION OF THE MAGNET COIL BY A CONTROL CIRCUIT, AN OVERLOAD RELAY DEVICE, MEANS DETACHABLY CONNECTING THE RELAY DEVICE IN A FIXED POSITION RELATIVE TO THE BASE, SPACED RIGID MALE CONNECTOR IN FIXED POSITIONS, RESPECTIVELY, ONE THE OVERLOAD RELAY DEVICE, AND EXTENDING ENDWISE, EXTERIORLY THEREOF AND CLAMPED BY THE CLAMPING MEMBERS IN CONTACT WITH THE TERMINAL PORTIONS, RESPECTIVELY, AND SAID FIXED POSITIONS OF THE MALE CONNECTORS AND THE POSITIOINS OF THE TERMINAL PORTIONS BEING SUCH THAT THE MALE CONNECTORS ARE ALIGNABLE WITH, AND WHILE ALIGNED ARE RECEIVABLE ENDWISE CONCURRENTLY IN A CLAMPING POSITION RELATIVE TO THEIR ASSOCIATED TERMINAL PORTIONS OF THE SWITCH DEVICE BY BODILY RELATIVE MOVEMENT OF THE DEVICES TOWARD EACH OTHER ENDWISE OF THE MALE CONNECTORS. 